02 super duty with 7.3 fuel gauge will give false readings.

Yes, it's in the gas tank, attached to the fuel pump/sending unit assembly.

I'm attaching 2 links to videos, tge second is to bypass this module. That'll fix the issue of a non functional gas gauge that always reads empty if you don't mind going that route. http://www.youtube.com/watch?v=yILXFS8X8pQ

Fix Ford Gas Gauge That Always Reads Empty The Anti Slosh Bypass

if you have 2 fuel gauges working of a tank switch there may be some resistance in the circuit of the second circuit that increases the reading of the gauge. Personally I have the tanks balanced out with a levelling hose between them the the gauge reads the capacity left in the tanks IE full-- both tanks-- full, 1/2 both tanks 1/2 With the way you have it set up then if one gauge is faulty and shows full when it is empty you can find yourself in a spot of bother when you need the other tank

most likely you will need to pull fuel pump assembly. might as well change the whole thing once in there and it was save time later

The fuel sending unit rod was bent during the instalation giving you the false readings. This is the thin metal rod that attaches the float to the sender.

hi it can really only be two things, first is the fuel sender on the pump inside the tank it could be stuffed or sticking causing a false reading, second it can also be a faulty fuel gauge on the dash.

Hi.
3 options.
1.The electrical coupler to the Fuel tank may have got corroded, creating a power "shunt".
2. The tank level foat, with has a rheostat on it has failed.
3. The tank Level Float has perforated, and the inducted fuel has made it "sink", giving a false reading in all cases.
Regards, DT

The Fuel level FLOAT, in the tank is defective. Possible that it "holed", and has sunk to the bottom of the tank.
To check, separate the harness plug to the Tank sender unit, and ground the supply to a suitable place on the frame. The dash gauge should record "Full", therefore the sender unit is suspect.
regards. DT

Ford has lots of problems with the sender reliability. Typically, the sender (and expensive fuel pump) replacement resolves the issue. To test, you need to take the connection off of the sending unit, at the tank, turn on ignition, and then ground and un ground it and view results at the gauge. If the gauge responds, the sender needs to be replaced.

There are aftermarket senders that cost less than OEM.

Check the harness connector at the fuel tank for a short to ground and test to see if the tank is properly grounded.

possible fuel pump and/or incorrect fuel reading...these senders in tank can give false reading to gauge.key on-engine off runs pump for 3 seconds...listen to the pump in a quiet place like a closed garage and alot of times these pumps sound odd when failing like a louder whining noise than normal. turning the key off for 5 secs will reset and run the pump once again when you turn key on but do not crank. fuel pump is fairly common failed item for this make and model.Replacing sender while servicing pump is reguarly done as well.